Add additional Homie implementations

[labodj]

Hi,

I would like to add three Homie-related projects I have been working on to the implementations page.

The first one is homie-v5, a maintained fork of homie-esp8266 for ESP8266/ESP32 Arduino projects. It
keeps Homie 3.0.1 as the default behavior, while also adding opt-in support for Homie 4.0.0 and Homie 5.x
metadata.

The other two projects are focused on Home Assistant MQTT discovery:

• homie-home-assistant-discovery, a Node.js library and CLI that maps Homie MQTT metadata to Home
  Assistant MQTT discovery payloads.
• node-red-contrib-homie-home-assistant-discovery, a Node-RED node built on top of the same core
  library, intended for users who prefer wiring this integration directly inside Node-RED flows.

I tried to keep the change small and limited to the existing implementations tables, without changing the
surrounding content or structure.

Validation done locally:

• checked the Markdown diff for whitespace issues
• verified the touched table rows keep the expected column structure
• verified that the npm and PlatformIO package entries are publicly available

I could not run the full Hugo build locally because Docker/Hugo are not available in my local checkout.

[Thalhammer]

Always nice to see new support for the specification, especially if it involves the new versions of it :)

[Tieske]

lgtm